Chapter 18: Metals

Metals

• Metals are found in group 1, group II and the Transition Block of the periodic table.
• As we go down the group there is an increase in metallic character.

Properties of Metals

Reactivity with water

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• Metals react with cold water and form a metal hydroxide and hydrogen gas

• [ ] metal + water → metal hydroxide + hydrogen

• [ ] For example calcium: Ca (s) + 2H2O (l) → Ca(OH)2 (aq) + H2 (g)

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Reactivity with acids

• metal + acid → salt + hydrogen

• [ ] Fe (s) + 2HCl (aq) → FeCl2 (aq) + H2 (g)

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Reactivity with oxygen

• metal + oxygen → metal oxide
  • [ ] 2Cu (s) + O2 (g) → 2CuO (s)

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Reactivity series

Reactions with Aqueous Ions & Oxides

• Example> COPPER (II) OXIDE

• [ ] Magnesium is above copper in the reactivity series,

• [ ] magnesium is more reactive so can displace copper from its oxide

• [ ] Copper is reduced

• [ ] The reducing agent in the reaction is magnesium: copper oxide + magnesium → copper + magnesium oxide

• [ ] CuO (s) + Mg (s) → Cu (s) + MgO (s)

Displacement reactions

• Displacement reactions between metals and aqueous solutions of metal salts

• [ ] Any metal will displace another metal that is below it in the reactivity series from a solution of one of its salts

• [ ] Magnesium + copper sulfate

• [ ] Magnesium is a reactive metal and can displace copper from a copper sulfate solution

, more reactive metal slowly disappears from the solution, displacing the less reactive metal.

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Decomposition reactions

• Thermal decomposition reactions: Some compounds decompose or breakdown when they are heated to sufficiently high temperatures

• These reactions are called thermal decomposition reactions.

• metal hydroxide → metal oxide + water

• [ ] Zn(OH)2 (s) → ZnO (s) + H2O (l)

• metal carbonate → metal oxide + carbon dioxide

• [ ] MgCO3 (s) → MgO (s) + CO2 (g)

• metal nitrate → metal nitrite + oxygen

• [ ] 2NaNO3 (s) → 2NaNO2 (s) + O2 (g)

• metal nitrate → metal oxide + nitrogen dioxide + oxygen

• [ ] 2Cu(NO3)2 (s) → 2CuO (s) + 4NO2 (g) + O2 (g)

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